Hi,
There appears to be a race condition where the editor icons don't always load.

This is more often than not the record audio, record video and H5P editor icons.

In this case the record audio happened to load while the next two failed.

This was tested on Moodle 5.0 on Mount Orange Moodle Demo as a teacher.

Replication steps:

1. open a private web browser window
2. login in to Moodle
3. go to course as teacher
4. turn edit mode on
5. edit a section and add an activity or resource
6. add a text area

Observe: some editor icons may be broken

Refresh the page and the icon images appear 

https://school.moodledemo.net/course/modedit.php?add=label&type&course=69§ion=4&return=0&beforemod=0 

editor icon load race condition.mp4